Big turbo options

[Mattwurbo]

Hi all
im currently researching which turbo to go with for my build. I have bought a td06 20g which is getting sent back as a couple of guys I know are running them and aren't getting the real power they should be and, according to an extremely reputable tuner, aren't suitable for our 1.8t engines. Granted, they're making around 430bhp respectively, they are still not ideal.
i have personally now been looking at the gt3071r and the gt3076. My target power is between 450-500bhp. My question is how 'laggy' would the gt3076 be in comparison to the gt3071r and a what rpm would they both be at full chat?? According to the stickies there's only 100rpm difference! I find that quite hard to believe. Any other turbo suggestions and constructive comments are extremely welcome. Thanks in advance

 

[<tuffty/>]

Depends on your definition of laggy and how you go about your build... my stroker/GT3582r 'spools' later than my 1.8/GT3071 setup but... makes more power on less boost everywhere...

Red line is stroker/GT35 and blue is 1.8 and GT30

Anyone that wobbles on about lag on a BT hasn't driven one IMO... mine feels fantastically drivable on the road off boost and when on boost there is no let up between gear changes...

If you want to be cruising at 70 in sixth and expect it to pick up without changing down to an appropriate gear then buy a diesel

Personally I am not that impressed with the GT3076 over a GT3071... I'd rather use the Owens Developments M-Spec GT3071 with HTA billet comp wheel... however... you are still only looking at mid 400's... GT35 if you fancy 500hp...

Whatever you do though... build it all on a stroker... doesn't matter what turbo you buy, stroker will make it that much better

<tuffty/>

 

[snowy]

stroking things is good for you, science has proven this

 

[millsy75]

Thanks Tuffty, as always helpful info

I was planning to go hybrid but have realised it won't cut it for me power wise so I was thinking either GT2871R or GT3071R. I'm not stroking just rod job in the 1.8.

So this Owens M spec GT30 would be a much better option for me for power and day to day use you think than the garrett turbos I listed above?

Thanks.

 

[Gops]

Gt35 ftw! Well that's what I'm doing. Tuffty teased me enough

 

[millsy75]

That'll be way too laggy on a 1.8 though won't it mate!!!

 

[<tuffty/>]

That'll be way too laggy on a 1.8 though won't it mate!!!

Gops may have forgotten to mention he is going stroker too ;P

<tuffty/>

 

[superkarl]

people dont realise that if you have the right mods in place with BIG turbos (headwork and valvetrain) that the powerband is moved drastically to the right. They just think 'oh it spikes at 4.5k, thats no good' probably comparing it to their stock rev limit of 7k. But it will make its power past 8k, thats 4000rpm of insane power! way more of a power band than any stock turbo that might be singing at 3k.

 

[millsy75]

Exactly mate "with the right mods" £££

I am only planning uprated rods. Hybrid power won't satisfy me. Have you experienced a 1.8 on either of the turbos I mentioned? Or has anyone first hand experience of the GT30 tuffty mentioned?

Turbo choice is a minefield and I want to get it right. Daily driver but with around 400 usable ponies

 

[millsy75]

What is a realistic cost to stroker and GT35 the 1.8? 6K?

 

[<tuffty/>]

What is a realistic cost to stroker and GT35 the 1.8? 6K?

http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/217857-how-much-$$$-would-500-bhp-cost.html

<tuffty/>

 

[S3Alex]

Depends on your definition of laggy and how you go about your build... my stroker/GT3582r 'spools' later than my 1.8/GT3071 setup but... makes more power on less boost everywhere...

Red line is stroker/GT35 and blue is 1.8 and GT30

Anyone that wobbles on about lag on a BT hasn't driven one IMO... mine feels fantastically drivable on the road off boost and when on boost there is no let up between gear changes...

If you want to be cruising at 70 in sixth and expect it to pick up without changing down to an appropriate gear then buy a diesel

Personally I am not that impressed with the GT3076 over a GT3071... I'd rather use the Owens Developments M-Spec GT3071 with HTA billet comp wheel... however... you are still only looking at mid 400's... GT35 if you fancy 500hp...

Whatever you do though... build it all on a stroker... doesn't matter what turbo you buy, stroker will make it that much better

<tuffty/>

Spot on as usual!

Mine I guess would be the equivalent of a stroker at 2litres,but the principle is the same,and the same comments about lag,spool,and power delivery apply.

Yes,there is a huge step at 4000rpm,but it runs right through to over 7000rpm,with no sign of giving up,where the previous turbo(a GT3071) was running out of puff,and that's only more obvious against the original K04 which was pretty much done by 6000rpm.

Around town,off boost,it gets along very well,and is actually better than the car was originally.

On the subject of which turbo to choose,Owen Developments were fantastically helpful,and my original BT kit had a GT3071,which was prone to surge,and also pretty much wrung out by 480-500bhp.
The eventual replacement was a GTX 3076,which has sufficient flow for up to 640bhp,and kind of took me off the idea of the GTX3576 which doesn't flow a great deal more in any case,or the GTX3582.

Owen also fitted the metal bearing cage,which is a must if you use a heat jacket or ceramic coating to keep heat radiation down.

The other thing is matching the turbo to the engine and application,and that's one of Owen's real strengths.

 

[badger5]

compressor having sufficient flow and realising its potential in actual power however is not a Given!

k04 hybrids for years have been sold as 350-360bhp level units based on their comp wheel flow specs............ We know realities were not realised until a bunch of decent well supporting "other mods" joined the party.

Fixating on single components is a fools game... Not saying you are Alex, but I know others do who read this forum... and they are going to be disappointed. sum of the parts, and correct mix of parts and build is what brings it together to perform..



.

 

[S3Alex]

compressor having sufficient flow and realising its potential in actual power however is not a Given!

k04 hybrids for years have been sold as 350-360bhp level units based on their comp wheel flow specs............ We know realities were not realised until a bunch of decent well supporting "other mods" joined the party.

Fixating on single components is a fools game... Not saying you are Alex, but I know others do who read this forum... and they are going to be disappointed. sum of the parts, and correct mix of parts and build is what brings it together to perform..



.

I totally agree.

I said at the end of my post that one of Owen's strengths is in working with the customer to try and provide the best match to the engine and application,and whilst that goes some of the way,as you say,it doesn't guarantee results.

The sum of the parts doesn't always add up to the expected result,and then you get disappointment when it doesn't deliver.

I've always tried to look at the whole picture of what I'm trying to do,but the advice of others who've either done it themselves,or have wider experience has always been very helpful to me,and I know that for instance it's all very well theoretically being able to squeeze sufficient fuel and air for 500bhp into the engine,but it won't work if it can't all get out the other end so to speak.

I'm not mechanically proficient,but I've seen some truly awful things through the last 20yrs of having my cars "tuned",and thankfully,apart from one experience with a well known(at the time) Cosworth tuner whose idea of a clean room was building heads on a piece of cardboard on the shop floor,allied to engine installs that looked like a rat's nest,I've been very lucky to have people who either have the required skills,or acquire them.

I think that a lot of folk simply look at a pile of parts,add them up and say it equals "x" bhp.

 

[S3Alex]

The other thing I meant to say is that in the 8L section,you guys have a HUGE amount of experience with this engine,and the expertise to back up what you say.

I look in here often and am still in awe of the quality of the work going on,whereas in the 8P(and more so now in the 8V) sections,a lot of work is still basically development or trial and error.

We still find ourselves sharing ideas and learning what does and doesn't work,and there aren't a huge number of cars turning out in excess of 250bhp/litre even now.

Take the PCV kludge.....you guys have gone way past that,and we're only just getting decent aftermarket breather systems to eliminate it.

 

[badger5]

I think that a lot of folk simply look at a pile of parts,add them up and say it equals "x" bhp.

yep.
so true.
and that includes some "mappers" who have little actual experience of the hardware yet preach like they have a clue to customers about hardware.

1+2+3 tuning does not always equal 6

 

[S3Alex]

yep.
so true.
and that includes some "mappers" who have little actual experience of the hardware yet preach like they have a clue to customers about hardware.

1+2+3 tuning does not always equal 6

That formula sometimes comes to 1+2+3 = Bang ..... in the wrong hands simple things can become grenades.

 

[Gops]

From my point of view big turbo projects can look very appealing for people like us.. But it's lots of planning and work to achieve a good result! Everything has to be looked at in detail if you want a success.. From my experience, stick with one builder/tuner as it can go abit pear shaped if you use many people! I'm in talks with our dearest Bill about my forthcoming project but I seriously need to save up as it's not cheap whatsoever!! I'm lucky I have a few bits (valvetrain + rods albeit a few valves missing) so that helps with cost! I also already have a block spare with a large port head so providing it's cylinders aren't too oval then it's a gooden! I got it wrong first time because it was rushed. Do it right first time, it'll pay it's dividends!

 

[S3Alex]

From my point of view big turbo projects can look very appealing for people like us.. But it's lots of planning and work to achieve a good result! Everything has to be looked at in detail if you want a success.. From my experience, stick with one builder/tuner as it can go abit pear shaped if you use many people! I'm in talks with our dearest Bill about my forthcoming project but I seriously need to save up as it's not cheap whatsoever!! I'm lucky I have a few bits (valvetrain + rods albeit a few valves missing) so that helps with cost! I also already have a block spare with a large port head so providing it's cylinders aren't too oval then it's a gooden! I got it wrong first time because it was rushed. Do it right first time, it'll pay it's dividends!

So true.

It's easy to do something in haste and buy twice,or have to spend a lot more putting it right.

When you find someone who knows what he's doing,like Bill,it turns a minefield into a stroll,or something along those lines.
I tend to get an idea for something,and then spend ages checking it out with my tuners,and then more time putting all the right bits together before trying it.
I've also been fortunate enough to have a few good friends who've done a lot of the work before me,and are good enough to share their results.